The present invention relates to a suction air nozzle for forming a thread reserve, in which a passing thread undergoes intermediate storage in the form of a loop and which has an elongated cross-section of which a larger inside dimension extending in the direction of thread travel is substantially greater than a smaller inside dimension.
The method of intermediate storage of the thread with a device of this kind for thread tension equalization is known (DT-OS 1 785 321). Although, due to the suction air nozzle having an elongate cross-section, swirling of the thread is rendered difficult, it nevertheless happens that the thread forms knots which must then be separated from the thread in a separate rewinding process.